A THUMB-TIP—which is called kustubān by the Persian and khayta‘ah by the Arabs—consists of a
ring or leather or some other material. It is worn over the right thumb, leaving the nail and knuckle
exposed, and is use for the protection of the thumb against injuries which are usually caused by the
string when it is drawn and release (Its use is necessary except when the archer employs a very weak
bow for executing some stunt or for shooting at near target. Shooting without a thumb-tip, whenever
possible, is better and offers greater accuracy. For this reason [to resemble the bare skin], a thumbtip
should be mad of leather that is even in texture and moderate in thickness, and should be lined
with very fine leather and sew with great care. An almost invisible groove should be mad in it for the
string. The end which lies on the tip of the thumb should be fashioned like a small, broad bean of
moderate thickness; not so long as to impede the string, so short as to fail to protect the thumb from
the action c the string. In width it should be the same as the thumb itself, with its back part a little
narrower than its front part. The side of the leather that is smoothed in the tarning should be next to
the string.

Thumb-tips are often made of the skin of horses or goats, or of other kinds of tanned hides, as well
as of silver, copper, iron, bone and horn. The last variety is made b taking a fine horn, large enough
to hold the thumb, an cutting it down to the right size; then a piece is carved out to expose the nail
and the knuckle of the thumb, and groove for the string is marked on the face of it. The same process
is followed in making tips of silver or other metals.

The best thumb-tips, however, are made of leather of moderate thickness, neither too thick lest they
interfere with the efficiency of shooting, nor too thin lest they fail to protect the thumb against the
action of the string.

Leather tips are superior to those of silver and the other metals because they are
soft and flexible and interfere least with the accuracy of shooting. Some archers, however, hold that
tips of silver or of other metals are better than tips of leather in competitive and distance shooting.
Ṭāhir al-Balkhi said that for distance shooting thick tips are better, while for accurate target shooting
thin tips are superior. This is, in fact, correct.